Systematic Reviews
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Diabetes. Dec 15, 2019; 10(12): 560-580
Published online Dec 15, 2019. doi: 10.4239/wjd.v10.i12.560
Correlating the global increase in type 1 diabetes incidence across age groups with national economic prosperity: A systematic review
Natalia Gomez-Lopera, Nicolas Pineda-Trujillo, Paula Andrea Diaz-Valencia
Natalia Gomez-Lopera, Nicolas Pineda-Trujillo, Grupo Mapeo Genetico, Departamento de Pediatría, Facultad de Medicina, Universidad de Antioquia, Medellín 050010470, Colombia
Paula Andrea Diaz-Valencia, Epidemiology Group. School of Public Health. Universidad de Antioquia, Medellín 050010470, Colombia
Author contributions: Gomez-Lopera N and Diaz-Valencia PA conducted the data collection and analyses; Gomez-Lopera N, Diaz-Valencia PA and Pineda-Trujillo N contributed to the writing of the manuscript. All authors read and approved the final manuscript.
Supported by doctoral scholarship (Natalia Gomez-Lopera) from Colciencias, No. 727.
Conflict-of-interest statement: The authors declare no conflict of interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 checklist.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Natalia Gomez-Lopera, BSc, PhD, Academic Research, Research Scientist, Pediatrics, Departamento de Pediatría, Facultad de Medicina, Universidad de Antioquia, Carrera 51D No. 62-21, Medellín 050010470, Colombia. natalia.gomezl@udea.edu.co
Telephone: +57-4-2106065 Fax: +57-4-2196069
Received: March 8, 2019
Peer-review started: March 11, 2019
First decision: March 10, 2019
Revised: October 17, 2019
Accepted: October 27, 2019
Article in press: October 27, 2019
Published online: December 15, 2019
Processing time: 284 Days and 2.2 Hours
ARTICLE HIGHLIGHTS
Research background

Type 1 Diabetes (T1D) is a complex disease resulting from the interplay of genetic, epigenetic, and environmental factors. There is a dramatic increase in the incidence of T1D, predominantly in younger children (0-4 years old) worldwide. The cause of this increase is still under study.

Research motivation

This work updates the current knowledge on the global incidence of T1D across age categories and its variation over time. The increase of incidence of T1D has been associated with socioeconomic factors, such as gross domestic product (GDP). However, there have been conflicting results about the relationship between income level and the incidence of T1D.

Research objectives

We searched the global variation in the incidence of T1D in the age categories and two periods (1975-1990 and 2000-2017). We then searched to what extent these variations correlated with the GDP per capita in these countries.

Research methods

We updated through a systematic review, our previous results on the global incidence of T1D in individuals aged 0-14 years. We first retrieved the incidence of T1D data in different age categories (0-4, 5-9, 10-14, 0-14) and divided the incidence information into two periods (1975-1999 and 2000-2017). Then, we conducted an exploratory ecological analysis about the relations of population rates of T1D incidence and the average GDP of these countries. Comparisons of means, correlations, linear regression were made.

Research results

We retrieved incidence data for 84 countries, most of them are European. We observed an increase in the incidence of T1D worldwide when comparing the periods 1975-1999 and 2000-2017. We also observed an increase in the incidence of T1D in all age categories (0-4, 5-9 and 10-14). In the period 1975-1999, the incidence increased with age, with a peak in children aged 10-14 years. For the period 2000-2017, there appeared to be an increasing number of patients in the 5-9 age group and a greater relative rise in the 0-4 age group. Also, we found that the highest incidences of the disease were reported in wealthier countries.

Research conclusions

We found a wide geographic variation in the incidence of T1D and a worldwide increase in the two periods considered in this study, especially in younger children (0-4 years old); showing an early age at onset. Also, we confirmed that there was a positive correlation between the socio-economic level and the incidence of T1D. More studies are required to elucidate the interaction between environmental, immunological and genetic factor.

Research perspectives

This study showed the enormous differences in surveillance and epidemiological reports of T1D worldwide. Most of the countries retrieved from the systematic review are European and few studies were carried out in Central and Latin America, Central Asia and Sub-Saharan Africa. It is very important that the scientific community generates more studies on the epidemiology of T1D that contribute to understanding the changes in the dynamics of the disease.